[Clinical evaluation of different angulation radiograph in diagnosing multiple canals of mandibular first premolars in vivo].

OBJECTIVE: To investigate the efficiency of different angle projection radiograph in diagnosing multiple canals of mandibular first premolars. METHODS: Eighty-eight mandibular first premolars that needed endodontic treatment in vivo were selected. The radiograph was taken at a horizontal angles of 0, 20-30 degrees from mesial or distal direction of the tooth preoperative. According to the different angle projection radiographic evaluation, radiographic diagnosis of multiple canals were suspected. After the root canal orifice were detected and located with K files, the root canals were prepared using crown-down technique and obturated using cold lateral condensation technique. The configurations and numbers of root canals were identified and recorded. The postoperative radiograph was taken. According to configurations and postoperative radiograph, the root canal configuration was classified into type I -V. RESULTS: In eighty-eight mandibular first premolars, 31 multiple canals teeth were suspected in preoperative radiographic diagnosis, 30 multiple canal teeth were detected under clinical evaluation. In case of 31 multiple canal teeth suspected by preoperative radiographic diagnosis, 3 teeth were not found multiple canals under clinical evaluation. While in case of 2 teeth of one canal suspected by preoperative radiographic diagnosis, multiple canal was detected under clinical evaluation. In 31 multiple canal teeth suspected by preoperative radiographic diagnosis, 13 teeth were detected at a horizontal angles of 0 degree and 25 teeth were detected at a horizontal angles of 20-30 degree, 7 teeth were suspected at different angle projection. Clinical detected rate of multiple canal in mandibular first premolar were 34.09% (30/88), 70.00% of which were type IV and V. CONCLUSION: Different angulation radiograph of preoperative will assist to increase clinical detection rate of multiple canals in mandibular first premolar.

[Clinical evaluation of the effect of angulation apical X-rays and the X-rays with file in diagnosing multiple canals in mandibular anterior teeth and premolars].

OBJECTIVE: To investigate different angle projection technique for the clinical detection and treatment of multiple canals in mandibular anterior teeth and premolars. METHODS: Two hundred and forty-seven in vivo mandibular anterior teeth and premolars were selected from two hundred and fourteen patients. Four kinds of radiographs were taken for each tooth. The radiograph was taken at a horizontal angles of 0, 20 - 30 degrees from the mesial or distal of the tooth with and without files in canal. If a radiolucent line or files was present mesial or distal to the main canal, an additional canal was suspected. If the tooth appeared to have one large canal in the cervical or middle third of the root which disappeared or constricted as it traveled in an apical direction, an additional canal was suspected. The root canals were instrumented with ProTaper in crown-down mode and filled with laterally condensed gutta-percha and paste, the root canal configurations were classified into Types I - V. RESULTS: 60.92% multiple canals and 26.44% long oval canals were detected and treated from suspected multiple canals. The sensitivity of angle projection technique with file in X-ray diagnosing of multiple canals was 93.0%, and second canal was missed in four cases. The multiple canals in the 247 mandibular anterior teeth and premolars were present in central incisors: 9.43% (5 of 53); lateral incisors: 38.33% (23 of 60); canines: 15.90% (7 of 44), first premolar: 40.38% (21 of 52); second premolar: 2.63% (1 of 38). CONCLUSIONS: The different angle projection technique will assist the clinician in the detection and treatment of multiple canals in mandibular anterior teeth and premolar, and angle projection technique with file detected more multiple canals.

[Comparative study of resosolv and chloroform in retreatment of canal obturated with resinifying agent].

OBJECTIVE: To evaluate the possibility for removal of resinifying agent, time required for removal and the working length loss by Resosolv or Chloroform. METHODS: 40 human teeth (80 root canals) obturated with FR phenolaldehyde agent were divided into four groups, 20 root canals per group. Group A: Resosolv with K file; group B: chloroform with K file; group C: Resosolv with Ultrasonic K file; group D: Chloroform with ultrasonic K file. Calculating the pereentage for removal of resinifying agent, time required for removal and the working length loss. RESULTS: The effectiveness of Resosolv for removing resinifying agent was better than chloroform. 87.5% of canals could be negotiated by Resosolv; 45% of canals be negotiated by chloroform. CONCLUSION: Resosolv is an effective solvent for canals obturated with resinifying agent.